Man could not live, act and remain sane, unless he can succeed in satisfying certain necessities which are the psychological concomitants of the biological essence of man. He needs to be related to other human beings. He needs to have a frame of orientation [and an object of devotion] which permits him to place himself at a certain point on an ordered picture of the universe. He needs to have a character structure (in the dynamic sense) which is a substitute for instincts inasmuch as it permits him to act semi-automatically, without having to make a decision before every action, and to act consistently. These general human necessities constitute, in my view, human nature in its psychological aspect as a result of its biological contradiction.
This concept of human nature and its necessity does not imply which particular kind of frame of orientation (and, as I forgot to say above, of devotion) and which particular kind of character traits an individual or a group has. These are all created within the historical process, as adaptations to the particular social structure in which individuals live. One social structure will be conducive to cooperation and solidarity another social structure to competition, suspiciousness, avarice; another to child-like receptiveness, another to destructive aggressiveness. All empirical forms or human needs and drives have to be understood as results of the social practice (in the last analysis based on the productive forces, class structure, etc., etc.) but they all have to fulfill the functions which are inherent in man’s nature in general, and that is to permit him to relate himself to others and share a common frame of reference, etc. The existential contradiction within man (to which I would now add also the contradiction between limitations which reality imposes on his life, and the virtually limitless imagination which his brain permits him to follow) is what I believe to be one of the motives of psychological and social dynamics. Man can never stand still. He must find solutions to this contradiction, and ever better solutions to the extent to which reality enables him.
Erich Fromm, Human Nature and Social Theory